Assassin's Creed PC game shows blank screen with the sound

Today Yesterday I have bought a Assassin's Creed Rogue game and installed in my system. I have 1GB graphics card and met the minimum system requirement of the game. But while I started the game, game starts and I could see only blank screen with the sound.
Let me know how to fix this or tell me whether it won't work in 2GB graphics card.